Minnesotans were rightly horrified to find yet another of their elected officials, Democratic U.S. Sen. Al Franken, the latest on a rogues’ list of powerful men who stand credibly accused of sexual misconduct.

Radio host Leeann Tweeden came forward Thursday to accuse Franken of groping and forcibly kissing her when the two were on a 2006 USO Christmas tour in the Middle East. Tweeden said that over her objections, Franken wanted to rehearse a kiss he had written into a skit. “He came at me, put his hand on the back of my head, mashed his lips against mine and aggressively stuck his tongue in my mouth,” she said. When she rejected him, Franken retaliated with “petty insults” that culminated in a photo taken while she slept aboard a military transport that showed Franken leering into the camera with his hands over her breasts.

In apologizing, Franken said he didn’t recall the rehearsal incident “in the same way,” although he declined to say exactly how he remembered it. He also used an increasingly tired dodge, saying the photo “clearly was intended to be funny but wasn’t.” Let’s be clear: The photo was never intended to be funny. It was a mean attempt to humiliate and denigrate a fellow USO volunteer who had the temerity to reject his advances.

We’ve heard the humor defense before. Franken’s initial Senate run suffered over his history of profane and at times misogynistic humor, which included a 1995 proposed “Saturday Night Live” sketch on the comedic “rape” of CBS reporter Lesley Stahl. In apologizing to the DFL Party convention in 2008, Franken resorted to saying he had come to realize some of his jokes “weren’t funny.” The apologies are wearing thin.

This Editorial Board in recent days called for the resignations of state Sen. Dan Schoen, DFL-St. Paul Park, and state Rep. Tony Cornish, R-Vernon Center, for multiple accusations of ugly sexual misdeeds while in office. Franken, so far, is accused of one incident that occurred before he took office. That does not excuse or mitigate the gravity of his conduct, which was despicable, but the story was still developing as this editorial was being written.

Franken now faces what is sure to be a prolonged Senate Ethics Committee investigation led by Republicans as they try to salvage the candidacy of one Roy Moore, an Alabama Republican who stands credibly accused of sexually assaulting a string of young women, one as young as 14. Franken’s scandal simultaneously provides cover for them and damages his ability to be an effective moral voice for Minnesotans — perhaps too much for him to continue in the Senate.

Minnesota DFL Party Chair Ken Martin commended Tweeden for “courageously coming forward” to share her story and said “we are incredibly disappointed in Senator Franken. … There is no excuse for his actions, whether they occurred before he was in the U.S. Senate or not.” We share that disappointment.